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Insulate loft and cavity walls

Insulation is easy to arrange, leaves very little mess and could save you hundreds of pounds a year. What’s more, you’ll be helping to reduce your CO2 emissions.

For free advice on loft and cavity wall insulation call the Energy Saving Trust advice line on 0800 512 012 (0300 456 2655 from a mobile) between 9am – 5pm.

  1. How can I tell if I have cavity walls?
  2. How much will I save from loft insulation?
  3. How much will I save from cavity wall insulation?
  4. Does insulation cause a mess?
  5. How do I avoid rogue traders?
  6. My loft’s already insulated
  7. Will I have to clear out my loft?
  8. Are there any offers available to help cover the cost of the job?
  9. Will I have to fill in any forms?
  10. Will I reduce my CO2 emissions?
  11. Can I install insulation myself?
  12. What is the quick guide to insulation?

How can I tell if I have cavity walls?

Most houses built after 1920 have cavity walls. You can usually spot cavity walls from their depth (walls more than 260mm thick are probably cavity walls) and by the pattern of the bricks. If the bricks are all ‘side-on’, with their long sides showing, there is probably a cavity. (If the pattern is mixed, with some bricks showing the shorter end-piece, they are probably solid, but do remember that solid walls can also be insulated.).

How much will I save from loft insulation?

Loft insulation is a layer of material formed into a thick quilt that’s rolled out between the wooden beams that run across the floor in the loft. The savings on your heating bill from installing loft insulation are illustrated in the table below.

 

Loft insulation (0 - 270mm) Loft insulation
(50 - 270mm)
Annual saving per year (£) Around £150 Around £45
Installed cost (£) Around £250 Around £250
Installed payback Around 2 years Around 6 years
DIY cost £250 - £350 £200 - £300
DIY payback 2 - 3 years 5 - 7 years
CO2 saving per year Around 800kg Around 230kg

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How much will I save from cavity wall insulation?

Cavity wall insulation (which can be a range of materials including glass wool, cellulose, and polyurethane) is blown into the gaps between your walls by a skilled installer. It saves around £115 every year from your heating bill (based on a three bedroom semi-detached house).

Measure Annual saving per year (£) Installed cost (£) Installed payback CO2 saving per year
Cavity wall insulation Around £115 Around £250 Around 2 years Around 610kg

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Does insulation cause a mess?

There’s no mess. For cavity wall insulation, the insulators usually don’t have to come inside your house, while for loft insulation the fitters will only be in your roof space for a couple of hours to roll out layers of insulation. There will be no damage to your house. You can also install loft insulation yourself.

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How do I find registered installers?

The Energy Saving Trust (EST) provides a list of trade-registered installers.

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My loft’s already insulated

Fewer than 1 in 10 homes have the recommended amount of insulation. Check with a tape measure that your loft insulation is 270mm thick. If it isn’t, you could be saving money, and cutting your carbon footprint, by adding more insulation.

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Will I have to clear out my loft?

Yes you will have to clear out your loft before the installer arrives. However, clearing your loft is a great opportunity to see what you have hiding up there – things to recycle, others to sell, and maybe some nostalgic items to treasure all over again.

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Are there any offers available to help cover the cost of the job?

Offers may be available – check to see what offers might be available from energy suppliers or others in your area by using the Energy Saving Trust grants and offers finder.

There is also the Warm Front initiative from the Government, with financial assistance of up to £3,500. Those who may be entitled to the offer include people aged over 60, or in receipt of income support, incapacity benefit, disability living allowance, housing benefit, council tax benefit and many other benefits. It costs nothing to apply.

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Will I have to fill in any forms?

Many householders will be entitled to financial assistance to help cover the cost of insulation, but the insulation installer will do any paperwork that is required.

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Will I reduce my CO2 emissions?

By drastically cutting the heat you’re losing from your home you’ll also reduce your carbon footprint.

You could cut your CO2 emissions by 600kg per year by installing cavity wall insulation and 800kg per year by installing the recommended level of loft insulation.

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Can I install insulation myself?

Loft insulation is a job that you can do yourself, as this video explains.

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What is the quick guide to insulation?

Q. How can I find an installer?
A. Go to the Energy Saving Trust’s website.
Q. Will the installer be registered?
A. Yes, the installers listed on the Energy Saving Trust’s site are registered.
Q. How do I arrange an appointment with the installer?
A. Simply call the installer and he or she will make an initial no obligation assessment, then discuss the offers that are available to help cover the cost of the job.
Q. How can I apply for the offers that are available to help cover the cost of the insulation?
A. The installer applies for the offers and gives you a price for the insulation, taking into account the offers you are eligible for.
Q. Will fitting insulation cause any mess?
A. No. Insulating the loft won’t affect the rest of the house and cavity walls are insulated from outside. Both jobs shouldn’t take more than a couple of hours each to complete.
Q. How much will insulation save on my heating bills?
A. You could save over £100 every year on your heating bills, depending on the insulation you need and have installed.
Q. Will insulation improve the energy performance of my house?
A. Yes. A properly insulated house has a significantly better energy performance than a house that does not have adequate insulation.
Q. Will insulation reduce my carbon footprint?
A. Insulating your home to the recommended levels will significantly reduce your CO2 emissions.

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Energy Saving Trust
advice line

For free advice on loft and cavity wall insulation call

0800 512 012
0300 456 2655 from a mobile
Open 8am – 7pm Monday to Friday

Cavity wall insulation

Save money. Save energy.

We all want to save as much as we can these days. And it's good to know that by doing yourself some good you're also doing the right thing by the environment.